Field of the Invention
The invention relates to a heat exchanger, particularly a charge air cooler or an exhaust gas cooler for a motor vehicle.
Description of the Background Art
An exhaust gas heat exchanger, which consists of a stack surrounded by a housing, is known from EP 1 348 924 B1, which corresponds to U.S. Pat. No. 6,920,918, whereby the stack is formed of flat tubes and each flat tube contains a turbulator, whereby the exhaust gas flows through each flat tube. A coolant channel, designed with flow directing elements through which the coolant taking up the heat of the exhaust gas is conducted, is formed in each case between two flat tubes.
To be able to better compensate rising exhaust gas temperatures, an exhaust gas heat exchanger is known from DE 10 2006 005 362, which corresponds to U.S. Pat. No. 8,020,610, in which the flow directing elements consist of a corrugated plate. Channels with inlets and outlets, which extend in the longitudinal or transverse direction of the exhaust gas heat exchanger, are formed in this plate. In both solutions, the exhaust gas channels are surrounded by a coolant-conducting housing, which has a substantial weight and contributes greatly to the cost during the production of the exhaust gas heat exchanger.
EP 1 762 807 B1, which corresponds to US 2007/0023174, discloses a heat exchanger with plate pairs each forming a fluid channel, whereby exhaust gas flows through the fluid channel. Individual channels which conduct the coolant are formed between the plate pairs, whereby the fluid channels conducting the exhaust gas delimit the heat exchanger outwardly and thus the hot fluid channels form the outer wall of the heat exchanger. To realize the coolant-conducting fluid channels laterally outward, embossings, which reduce the flow cross section of the exhaust gas-conducting fluid channel, are necessary in the exhaust gas-conducting wall regions of the fluid channel.